Door latching mechanism



Feb. 24, 1948- HARD";

noon LATCHING MEC-HANISM 2 Sheets-Sheet 1 Filed March 18, 1946 Fi liiil-l---l-I---- V w o PULL JREZL FIG/2 FIGJ INVENT R J. l-LHARDIE b1 miiw ATTORNEYS Patented Feb. 24, 1948 UNITED STATES, PATENT OFFICE noon LATCHING MECHANISM James H. Hardie, Montreal, Quebec, Canada, assignor to The Robert Mitchell Company Limited, Montreal, Quebec, Canada Application March 18, 1946, Serial No. 655,036

. 1 Claim. 1

This invention relates to improvements in door latching mechanisms of the so called push-pull type in which a spring projected latch bolt is retractable by means of a pivotally mounted pull handle located at one side of the door and a pivotally mounted push plate located at the opposite side of the door.

The present invention consists in the provision of a simplified assembly in which the shank of the bolt carries two cam surfaces facing toward the head of the bolt, one cam surface being positioned in the path of a bolt retracting element extending inwardly from the pull handle and the other being positioned in the path of a bolt retracting element extending inwardly from the push plate.

In the preferred embodiment of the invention a block is rigidly mounted on the shank of the bolt and corresponding end portions of the block lying above and below the shank of the bolt and facing towards the head of the bolt are inclined to provide the aforesaid cam surfaces. These cam surfaces are engaged by cooperating cam surfaces of the bolt retracting elements extending inwardly from the pull handle and push plate, one of said elements being arranged to pass transversely over the shank of the bolt and the other being arranged to pass transversely beneath the shank of the bolt.

Other characteristic features and advantages of this invention will be apparent from the following detailed description of the drawings, in which- Fig. 1 is a view of my improved latch mechanism as it appears when looking toward the edge of the door to which it is applied.

Fig. 2 is a view showing the latch assembly as it appears when looking toward the pull handle side.

Fig. 3 is a view showing the latch assembly as it appears when looking toward the push handle side.

Fig. 4 is a sectional view taken substantially along section line 4-4 of Fig. l.

Fig. 5 is a side elevational view of a latch bolt and cam block forming part of said mechanism.

Fig. 6 is a bottom plan view of the assembly shown in Fig. 5.

As shown in the accompanying drawing, in designates a door end provided with a door-locking mechanism generally indicated at I I. This mechanism includes a casing 12 fitted in the door in the usual manner and having a conventional lock bolt l3 slidably mounted in the upper portion ably mounted in the lower portion thereof.

The latch bolt I4 comprises a shank l6 and a head I! at the door edge end of the shank. The opposite end portion of the shank I3 is slidably mounted in the rear wall of the casing l2 and is encircled by a latch projecting spring I 8 confined I between said wall and a spring abutment l9 carried by the shank. A vertically disposed block 20 is mounted on shank It so that it projects above and below same. End portions of the block which .lie above and below the shank and face towards the head H are inclined to provide upper and lower. coplanar cam surfaces 2| and 22.

' Locking mechanism H is flanked on either side by side door plates 23 and 24 which are secured to door It! by suitable means. Door plate 23 is cut to receive a push plate 25 pivotally mounted at its upper end on pin 26 secured in brackets 21 on the inside of plate 23. The central portion of push plate 25 is provided with a bolt retracting arm 28 extending rearwardly therefrom through a suitable opening in the side wall of easing I2 and terminating in an inclined surface 29 substantially parallel to the upper cam surface 2| of block 20. When push plate 25 is forced inwardly the inclined surface 29 of arm 28 engages the surface 2| of block 20 in sliding engagement retracting the bolt against compression of the latch projecting spring I 8, drawing the head I! out of latching engagement to permit opening of the door.

Door plate 24 on the opposite side of the door is cut to receive a pull handle 30 pivotally mounted at its upper end on pin 3| secured in brackets 32 on the inside of plate 24. The lower portion of pull handle 30 is provided with a bolt retracting arm 33 extending rearwardly therefrom through a suitable opening in the side wall of casing 12 and passing transversely beneath the shank of the bolt. An upwardly projecting key 34 is mounted on arm 33 adjacent its free end. The forward end of key 34 is provided with an inclined surface 35 which lies substantially parallel to the lower cam surface 22 of block 20. When handle 30 is pulled outwardly arm 33 forces the inclined surface 35 of key 34 into sliding engagement with inclined surface 22, retracting the bolt to permit opening of the door.

' ,I claim:

" with an arm terminating in an inclined surface REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Malone Oct. 20, 1936 Zagrzejewski July 19, 1938 Knoll May 16, 1939 FOREIGN PATENTS Country Date France Nov. 16, 1934 

